The present invention relates to a method and apparatus for calculating sensor modelling coefficients, and more particularly to a method and apparatus for calculating sensor modelling coefficients for multiple sensor regions of operation.
In the field of sensor systems, for example pressure and/or temperature sensor systems, the characteristics of sensors vary between different regions of operation. For example, the characteristics of a temperature sensor within a first region of operation of, say, 0° C. to 85° C. may be significantly different to the characteristics of the temperature sensor within a second region of operation of, say, −40° C. to 0° C.
To compensate for such variations, it is necessary to carefully model the sensor characteristics across the different regions of operation. The characteristics of a sensor within a particular region of operation may be modelled using one or more equations, which may be used to provide, in the case of a temperature sensor for example, an estimated temperature value based on an output value from the respective sensor. In order for such equations to accurately model the characteristics of the sensor, accurate equation coefficients must be determined.
One conventional technique for determining such equation coefficients comprises collecting actual data for the sensor, for example actual temperature readings in the case of a temperature sensor, and thereafter calculating the equation coefficients using such actual data. In this manner, it is possible to determine accurate and reliable coefficients in order to enable the characteristics of the sensor to be accurately modelled. However, it is typically prohibitively expensive to take sufficient actual readings across multiple regions of operation for a sensor in order to determine accurate coefficients, and in particular that allows a smooth transition at the junction between adjacent regions of operation.
Thus, it would be advantageous to have a better method of determining sensor modelling coefficients.